Divisibility Rules
A. Divisibility by 2, 4, 8, 16, 32.
A number is divisible by 2, 4, 8, 16, 32,.. 2 n when the number formed by the last one, two, three, four, five…n digits is divisible by 2, 4, 8, 16, 32,..2 n respectively.
Example: 1246384 is divisible by 8 because the number formed by the last three digits i.e. 384 is divisible by 8. The number 89764 is divisible by 4 because the number formed by the last two digits, 64 is divisible by 4.
B. Divisibility by 3 and 9
A number is divisible by 3 or 9 when the sum of the digits of the number is divisible by 3 or 9 respectively.